Module version_check 

Functions

check_background

Spawn a background thread to fetch latest version from GitHub Releases and write the result to the lean-ctx data dir (latest-version.json). Non-blocking, fire-and-forget. Skips if cache is fresh (<24h). Respects update_check_disabled config and LEAN_CTX_NO_UPDATE_CHECK env var.

get_update_banner

Returns a formatted yellow update banner if a newer version is available. Reads only the local cache file — zero network calls, zero delay.

is_newer

SemVer precedence on MAJOR.MINOR.PATCH[-prerelease]: a prerelease sorts before its release (3.12.1-dogfood.9 < 3.12.1). Splitting the whole string on . read 3.12.1-dogfood.9 as 3.12.9, so dogfood and rc builds never saw their own release as an update.

session_update_hint

Returns a one-line update notification if available, exactly once per session. Safe to call from any tool — returns None after first notification.

version_info_json

Returns version info as JSON for the dashboard /api/version endpoint. Includes the cache age so the UI can be honest about staleness (#563).